Yes I saw that article also, for some reason the US seem to be on a mission re the E rating of fuels I read an article recently warning vehicle owners that they could invalidate their vehicle warranties by using some these higher grades and should check that their vehicle could actually use it before filling up.
I think we are only now going to E10 but it is interesting to know what is out there cos sure as eggs is eggs some bright spark will think that we should use it also.
The cultivator is usually very good at keeping us up to date with what is happening via the Federation of British Historic Vehicles folk. http://www.fbhvc.co.uk